Light-emitting keyboard and backlight module

ABSTRACT

A light-emitting keyboard includes a bracket, at least one keycap, a circuit layer and a composite light-emitting layer. The at least one keycap is disposed on the bracket and connected to the bracket via a support assembly. The circuit layer is disposed between the keycap and the bracket. The composite light-emitting layer is disposed under the bracket, and includes a substrate, a conductive layer, a reflective layer and at least one light source. The conductive layer is disposed on the substrate and includes a circuit and patterned structures. The reflective layer is conformally disposed on the conductive layer. The at least one light source is located under the at least one keycap and electrically connected to the circuit, and light emitted from the light source is transmitted upwardly to the keycap.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of and claims thepriority benefit of U.S. application Ser. No. 17/037,690, filed on Sep.30, 2020, now allowed. The prior U.S. application Ser. No. 17/037,690 isa continuation-in-part application of and claims the priority benefit ofU.S. application Ser. No. 16/528,592, filed on Jul. 31, 2019, nowpatented, which claims the priority benefit of U.S. provisionalapplication Ser. No. 62/712,993, filed on Aug. 1, 2018, and Chinaapplication serial no. 201910623300.8, filed on Jul. 11, 2019. Theentirety of each of the above-mentioned patent applications is herebyincorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a backlight module and a light-emittingkeyboard.

Description of Related Art

With the development of technology, light-emitting buttons have beendesigned to increase aesthetics or recognizability. In thelight-emitting button, a backlight module is mainly provided under abutton structure, and how to make the backlight module provide betteroptical effects and structural strength is the latest researchdirection.

SUMMARY OF THE INVENTION

The invention provides a backlight module having better structuralstrength and uniform lighting effect.

A light-emitting keyboard of the invention have the above-mentionedbacklight module.

A light-emitting keyboard includes a bracket, at least one keycap, acircuit layer and a composite light-emitting layer. The at least onekeycap is disposed on the bracket and connected to the bracket via asupport assembly. The circuit layer is disposed between the keycap andthe bracket. The composite light-emitting layer is disposed under thebracket, and includes a substrate, a conductive layer, a reflectivelayer and at least one light source. The conductive layer is disposed onthe substrate and includes a circuit and patterned structures. Thereflective layer is conformally disposed on the conductive layer. The atleast one light source is located under the at least one keycap andelectrically connected to the circuit.

A backlight module is adapted to be disposed under a button structure,wherein the backlight module includes a composite light-emitting layer,a light guide plate and a light-shielding layer. The compositelight-emitting layer includes a substrate, a conductive layer, areflective layer and at least one light source. The conductive layer isdisposed on the substrate and includes a circuit and patternedstructures. The reflective layer is conformally disposed on theconductive layer. The at least one light source is electricallyconnected to the circuit. The light guide plate is disposed on thereflective layer, and including at least one hole, and the at least onelight source located in the at least one hole. The light-shielding layeris disposed on the light guide plate.

In an embodiment of the invention, the substrate is a light-shieldingsubstrate.

In an embodiment of the invention, the substrate includes alight-transmitting film and a light-shielding coating disposed below thelight-transmitting film, and a portion of the circuit neighboring to thelight source is exposed by the reflective layer.

In an embodiment of the invention, the reflective layer is alight-reflecting coating, a light-reflecting film or a film withlight-reflecting coating.

In an embodiment of the invention, the patterned structures areelectrically insulated from the light source and are grounded.

In an embodiment of the invention, shapes of the patterned structuresare grid shapes, and a part of the reflective layer on the patternedstructures forms micro structures.

In an embodiment of the invention, the composite light-emitting layerhas a first long side and a second long side opposite to each other, theat least one light source includes a first light source close to thefirst long side and a second light source close to the second long side,the composite light-emitting layer further includes a first resistorelectrically connected to the first light source and a second resistorelectrically connected to the second light source, and a resistance ofthe first resistor is smaller than a resistance of the second resistor.

In an embodiment of the invention, the composite light-emitting layerhas a first short side, the at least one light source includes a firstlight source and a second light source, the first light source is closeto the first short side and located between the second light source andthe first short side, the composite light-emitting layer furtherincludes a light guide plate located on the reflective layer, the lightguide plate includes a first hole and a second hole, the first lightsource located in the first hole, the second light source located in thesecond hole, and a size of the first hole is greater than a size of thesecond hole.

In an embodiment of the invention, a length of the first hole along along side of the composite light-emitting layer is greater than a lengthof the second hole along the long side.

In an embodiment of the invention, a length of the first hole along thefirst short side is greater than a length of the second hole along thefirst short side.

Based on the above, the backlight module and the light-emitting keyboardof the invention includes the patterned structures of the conductivelayer, the patterned structures not only improve the structural strengthof the backlight module, but also help to form micro structures of thereflective layer such that the backlight module may provide uniformlighting effect.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and the drawings are incorporated intothe present specification and form a portion of the presentspecification. The drawings illustrate embodiments of the invention andare used to explain the principles of the invention with thedescriptions.

FIG. 1A is a top view of a light-emitting keyboard according to anembodiment of the invention.

FIG. 1B is an exploded view of a backlight module of the light-emittingkeyboard of FIG. 1A.

FIG. 1C is a partial cross-sectional view of the button structure withthe backlight module of FIG. 1B disposed thereunder.

FIG. 2A is an exploded view of a backlight module according to anotherembodiment of the invention.

FIG. 2B is a partial cross-sectional view of the backlight module ofFIG. 2A.

FIG. 2C is a partial view of the composite light-emitting layer of thebacklight module of FIG. 2A.

FIG. 2D is a diagram showing the positional relationship between a firstlight source, a first circuit, and a bracket of a button structure ofthe backlight module of FIG. 2A.

FIG. 3 is a partial cross-sectional view of a backlight module accordingto another embodiment of the invention.

FIG. 4A is an exploded view of a backlight module according to anotherembodiment of the invention.

FIG. 4B is a partial cross-sectional view of the backlight module ofFIG. 4A.

FIG. 4C is a cross-sectional view of another portion of the backlightmodule of FIG. 4A.

FIG. 5 to FIG. 7 are partial cross-sectional views of various backlightmodules according to other embodiments of the invention.

FIG. 8 is a partial cross-sectional view of the button structure with abacklight module according to another embodiment of the invention.

FIG. 9 is a projecting view of the light source, the bracket and thefirst light-shielding coating projected onto the keycap of FIG. 8 .

FIG. 10 to FIG. 15 are partial cross-sectional views of the buttonstructure with various backlight modules according to another embodimentof the invention.

FIG. 16 to FIG. 17 are partial cross-sectional views of variousbacklight modules according to other embodiments of the invention.

FIG. 18 is a projecting view of the light source, the first circuit, thesecond circuit and the first light-shielding coating projected onto thekeycap of the button structure with a backlight module according toanother embodiment of the invention.

FIG. 19 is a partial cross-sectional view along A-A section of the lightsource, the first circuit, the second circuit of FIG. 18 .

FIG. 20 is a partial cross-sectional view of a light-emitting keyboardaccording to an embodiment of the invention.

FIG. 21 is a partial cross-sectional view of a backlight module of FIG.20 .

FIG. 22 is a top view of the conductive layer and the bracket of thelight-emitting keyboard of FIG. 20 .

FIG. 23 is a partial enlarged view of FIG. 22 .

FIG. 24 is a circuitry diagram of the resistors, light sources, andcircuits of FIG. 22 .

FIG. 25 is a partial cross-sectional view of a backlight module of alight-emitting keyboard according to an embodiment of the invention.

FIG. 26 is a top view of the light sources, the light guide plate andthe bracket of the light-emitting keyboard of FIG. 20 .

FIG. 27 is a partial enlarged view of zone E of FIG. 26 .

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments of the invention are described indetail, and examples of the exemplary embodiments are conveyed via thefigures. Wherever possible, the same reference numerals are used in thefigures and the descriptions to refer to the same or similar portions.

FIG. 1A is a top view of a light-emitting keyboard according to anembodiment of the invention. FIG. 1B is an exploded view of a backlightmodule of the light-emitting keyboard of FIG. 1A.

Referring to FIG. 1A and FIG. 1B, a light-emitting keyboard 5 of thepresent embodiment includes at least one button structure 10 and abacklight module 100 located under the button structure 10. Lightprovided by the backlight module 100 illuminates the rear side of thebutton structure 10 to provide the user with an identification orvarious visual effects. The light-emitting keyboard 5 shown in FIG. 1Ais exemplified by, for example but not limited to, a keyboard of anotebook computer.

FIG. 1C is a partial cross-sectional view of the button structure withthe backlight module of FIG. 1B disposed thereunder. It should be notedthat, in order to clearly show the detailed structure of the backlightmodule, only a single button structure 10 is schematically shown in FIG.1C, and the relationship in size of elements included in the buttonstructure 10 and the backlight module 100 is only for schematicillustration.

As shown in FIG. 1C, in the present embodiment, the button structure 10includes a keycap 11, a support assembly 12, an elastic body 13, acircuit layer 14, and a bracket 15. The bracket 15 is disposed on thebacklight module 100 for holding the keycap 11, the support assembly 12,the elastic body 13, and the circuit layer 14 in position. The bracket15 may have a plurality of openings (such as through holes) that allowlight to pass through or to accommodate a light source. For example, therear surface of the keycap 11 may be illuminated by the light from thebacklight module 100 via openings 16 and 18, and the opening 16 mayaccommodate a first light source 140 of the backlight module 100 aswell. The number and arrangement of the openings of the bracket 15 arenot limited to the disclosure.

The circuit layer 14 is disposed between the keycap 11 and the bracket15. The circuit layer 14 is, for example, a flexible membrane circuit ina multi-layered structure having a conductive portion 17 as a switchingregion to trigger signals. The elastic body 13 is disposed between thekeycap 11 and the circuit layer 14, and provides a restoring force todrive the keycap 11 move up and return to its released state. Thesupport assembly 12 is disposed between the keycap 11 and the bracket15. The respective ends of the support assembly 12 are pivotably andmovably connected to the keycap 11 and the bracket 15, such that thekeycap 11 is stably moved up and down relative to the bracket 15 via theconnection of the support assembly 12. The support assembly 12 is, forexample but not limited to, a scissor-like mechanism that includes twosupporting pieces pivotally assembled together.

The elastic body 13 is located on the circuit layer 14 corresponding tothe conductive portion 17, wherein the elastic body 13 has a protrusionaligned with and disposed above the conductive portion 17. When thekeycap 11 is pressed to temporarily squeeze and deform the elastic body13, the protrusion of the elastic body 13 moves downward to press theconductive portion 17 of the circuit layer 14, such that the switch isturned on to generate an input signal. Once the applied force is removedfrom the keycap 11, the restoring force of the elastic body 13 drivesthe keycap 11 to move upward and return to the inactive (unpressed)position. In the present embodiment, the keycap 11 may have alight-transmitting portion 11 a defined by, for example, at least onecharacter represented by each button structure 10 to allow the lightemitted by the backlight module 100 to pass through, and thus alight-emitting button is obtained for user identification.

The backlight module 100 under the button structure 10 includes alight-reflecting plate 110, a light guide plate 120, and a compositelight-emitting layer 130 stacked from the bottom upwards to the top. Thecomposite light-emitting layer 130 is disposed between the bracket 15and the light guide plate 120, and the light guide plate 120 is disposedbetween the composite light-emitting layer 130 and the light-reflectingplate 110. As shown in FIG. 1B, the composite light-emitting layer 130located on the light guide plate 120 has a light-shielding pattern 133which may shade the regions that do not need to be illuminated by light,thereby avoiding light leakage. The composite light-emitting layer 130is provided with a light-transmitting region 138 where thelight-shielding pattern 133 does not cover, and the light can passthrough the light-transmitting region 138 to backlight the button. In anembodiment, in order to avoid light leakage between the buttonstructures 10, the light-shielding pattern 133 may be disposed under thegap between two adjacent keycaps 11, and the light-transmitting region138 could be surrounded by the light-shielding patterns 133. Thelight-transmitting region 138 is positioned corresponding to the keycap11, so that the light could be delivered to the button structure 10 ofthe light-emitting keyboard 5 (FIG. 1A).

In the present embodiment, the composite light-emitting layer 130includes a light-transmitting substrate 131, and a light-shielding plate134 located under the light-transmitting substrate 131. A first circuit139, the first light source 140, and a first passivation layer 142 arearranged on the light-transmitting substrate 131. The first circuit 139and the first light source 140 are disposed on one side of thelight-transmitting substrate 131, and the first light source 140 iselectrically connected to the first circuit 139. The first circuit 139includes a printed conductive paste or a patterned metal layer, such asprinted silver wiring or a patterned copper foil, but the type of thefirst circuit 139 is not limited thereto. After the first circuit 139 isformed on the upper surface of the light-transmitting substrate 131, thefirst light source 140 is disposed on the upper surface of thelight-transmitting substrate 131, such that electrodes of the firstlight source 140 are electrically connected to the first circuit 139.The light-transmitting substrate 131 and the first circuit 139 thereonare collectively used as a circuit board that supplies power to thefirst light source 140. The first passivation layer 142 covers the firstcircuit 139, such that at least a portion of the first circuit 139 islocated between the first passivation layer 142 and thelight-transmitting substrate 131, thereby preventing an open circuit ora short circuit caused by the damaged circuit pattern on thelight-transmitting substrate 131. In an embodiment, the firstpassivation layer 142 may further cover the first light source 140 toprotect both of the first circuit 139 and the first light source 140.The first passivation layer 142 is, for example, a flexible polymer filmhaving a thickness less than the thickness of the light-transmittingsubstrate 131.

As shown in FIG. 1B and FIG. 1C, the light-shielding plate 134 islocated between the light guide plate 120 and the light-transmittingsubstrate 131, and the light-transmitting region 138 is defined, by thelight-shielding pattern 133, on the light-shielding plate 134. Thelight-shielding plate 134 includes a film 135 and the light-shieldingpattern 133 formed on the surface of the film 135. In the presentembodiment, the film 135 is a light-transmitting substrate, and thelight-shielding pattern 133 includes a light-reflecting coating 136 anda light-shielding coating 137 layered on one side of thelight-transmitting substrate. If the light travelling in the light guideplate 120 is incident on the light-shielding pattern 133, the lightcould be reflected back into the light guide plate 120 by thelight-reflecting coating 136, while the light-shielding coating 137could prevent the light from being emitted out of the light-shieldingpattern 133. In an embodiment, the light-reflecting coating 136 is awhite paint, and the light-shielding coating 137 is a black paint. Thestructural configuration of the light-shielding pattern 133, and thecolors of the light-reflecting coating 136 and the light-shieldingcoating 137 are not limited to the disclosure.

The first light source 140 is disposed on the surface of thelight-transmitting substrate 131 distal to the light-shielding plate134. In the present embodiment, the light-transmitting substrate 131 hasits lower surface facing toward the light-shielding plate 134, and thefirst light source 140 is situated on the upper surface of thelight-transmitting substrate 131 and functions as, for example, atop-view light source. The first light source 140 is disposed in theopening 16 of the bracket 15 corresponding to the light-transmittingportion 11 a of the keycap 11, and therefore the first light source 140does not protrude from the upper surface of the bracket 15. Thus, thelight emitted by the first light source 140 under the button is adaptedto upwards and directly illuminate the button structure 10 a directionaway from the light-shielding plate 134 so as to provide a directionallybacklighting effect, thereby achieving independent light emission for asingle button. In other embodiments, the stacking positions of thelight-shielding plate 134 and the light-transmitting substrate 131 couldbe changed, such that the light-shielding plate 134 may be locatedbetween the bracket 15 and the light-transmitting substrate 131 havingthe light emitted from the first light source 140 not blocked by thelight-shielding plate 134.

The backlight module 100 further includes a circuit board 150 and asecond light source 160. The circuit board 150 is located under thelight-reflecting plate 110. A portion of the light-reflecting plate 110is disposed between the circuit board 150 and the light guide plate 120.The circuit board 150 is, for example, a flexible circuit board coupledto a power supply providing power to the second light source 160. Thesecond light source 160 is disposed under the composite light-emittinglayer 130, and is electrically coupled to the circuit board 150 throughpenetrating the light guide plate 120 and the light-reflecting plate110. For example, the light-reflecting plate 110 and the light guideplate 120 are respectively provided with openings 114 and 126 in whichthe second light source 160 is disposed, such that the second lightsource 160 positioned on the circuit board 150 could go upward and benext to one side of the light guide plate 120. The second light source160 is, for example, a side-view light source that could emit lighttoward the lateral side of the light guide plate 120. The light emittedby the second light source 160 is adapted to enter the light guide plate120 and travel over the interior thereof compliant with totalreflection, such that the light could be uniformly and evenlydistributed throughout the entire backlight module 100 and emitted outfrom the light-transmitting region 138 of the light-shielding plate 134to provide an optical effect of enhanced uniformity.

The first light source 140 and the second light source 160 may belight-emitting diodes respectively in different types or packages. Inthe present embodiment, the first light source 140 could be a chip-scalepackaged LED without leadframe or substrate, wherein a LED chip or dieis disposed on the light-transmitting substrate 131 in a flip-chipmanner, and the respective electrodes of the LED die are connected tothe first circuit 139 via a soldering or surface-mounting technique.Optionally, dispensing of gel with phosphor, if phosphor conversion isrequired, may be performed on the LED die, such that thelight-transmitting encapsulation (e.g., light-curable resin with orwithout phosphor) covers the die for protection and/or light conversion.Compared with the leadframe-based LED with the thickness of about 0.6mm, the miniaturized first light source 140 of the present embodimentadopts a chip-scale package without additional substrate and wirebonding, and therefore, the thickness of the first light source 140could be thinned to 0.08 mm or less. Moreover, the circuit for the firstlight source 140 is made from a printed conductive paste or a patternedmetal foil, which is much thinner than an ordinary circuit board (about0.15 mm to 0.2 mm). Therefore, the backlight module 100 could be slimmeddown by integrating the first light source 140 into the compositelight-emitting layer 130. It should be noted that the thicknesses of thecomponents shown in the figures only illustrate the relationship inposition and thickness, which are not limited thereto.

In the present embodiment, the second light source 160 of the backlightmodule 100 is, for example, a side-view light source, and the backlightmodule 100 could evenly and uniformly illuminate the buttons of thelight-emitting keyboard 5 via the second light source 160, thelight-reflecting plate 110, and the light guide plate 120. In addition,the first light source 140 of the backlight module 100 is, for example,a top-view light source. For a button having a special function (e.g.,hot keys) of the light-emitting keyboard 5, the backlight module 100,via the first light source 140, may provide localized backlighting whichis independently adjustable for the special hot keys, thereby allowingusers to quickly identify this button in a visual manner.

The configuration of the backlight module of the invention is notlimited to the backlight module 100. The following embodiments wouldelaborate other types of backlight modules. Except for the majordifference, the same or similar components as those of the previousembodiment are represented by the same or similar reference numerals andare not repeated hereinafter. In order to clearly show the detailedstructure of the backlight modules, the button structure is not shown insome figures, but it should be understood that the backlight modules ofthe following embodiments are adapted to be disposed under the buttonstructure to provide a button backlit effect.

FIG. 2A is an exploded view of a backlight module according to anotherembodiment of the invention. FIG. 2B is a partial cross-sectional viewof the backlight module of FIG. 2A. Referring to FIG. 2A and FIG. 2B, inthe present embodiment, a composite light-emitting layer 130 a of abacklight module 100 a includes the light-shielding plate 134 disposedon the light guide plate 120, and the first circuit 139 disposed on thelight-shielding plate 134. The first light source 140 is disposed on thelight-shielding plate 134 and electrically connected to the firstcircuit 139. That is, the light-shielding plate 134 and the firstcircuit 139 thereon are collectively used as a circuit board for thefirst light source 140. Compared with the embodiment shown in FIG. 1Band FIG. 1C, the light-transmitting substrate 131 of the compositelight-emitting layer 130 is no longer required in the compositelight-emitting layer 130 a of the present embodiment, such that theoverall thickness of the composite light-emitting layer 130 a may bereduced. The first circuit 139, the first light source 140, and thefirst passivation layer 142 previously on the light-transmittingsubstrate 131 shown in FIG. 1C are modified, in the present embodiment,to be directly disposed on the surface of the film 135 (such as thelight-transmitting substrate) of the light-shielding plate 134.

In the present embodiment, the first light source 140 and the lightguide plate 120 are located on two opposite sides of thelight-transmitting film 135. The first light source 140 is disposed onthe upper side of the light-shielding plate 134, while the light guideplate 120 is disposed on the lower side of the light-shielding plate134; that is, the first light source 140 is disposed on the surface ofthe light-shielding plate 134 distal to the light guide plate 120. Whenthe button structure is combined with the backlight module 100 a, theopening 16 of the bracket 15 shown in FIG. 1C may be used as theaccommodating space for the first light source 140, and the lightemitted by the first light source 140 illuminates toward a directionopposite to the light guide plate 120 to provide the individual buttonwith the independent and directional backlighting. The light emitted bythe second light source 160 is adapted to enter the light guide plate120 to provide an optical effect with uniform brightness, as depicted inthe above embodiment.

In addition, in the composite light-emitting layer 130 a, the firstcircuit 139 disposed on the light-shielding plate 134 could beelectrically connected to the circuit board 150. The first circuit 139laid out at an end 132 of the composite light-emitting layer 130 a is,for example, coupled to the circuit of the circuit board 150 via asoldering or hotbar bonding. That is to say, even if the first lightsource 140 and the second light source 160 are located on differentlayers, the interconnection therebetween could be conducted via thecircuit board 150, such that the single supply power could provide powerto the first light source 140 and the second light source 160.Accordingly, the circuit design can be simplified, and the respectivelight emission of the first light source 140 and the second light source160 could be independently controlled as well. In other embodiments, thefirst light source 140 and the second light source 160 may be connectedto different power supplies; that is, the first circuit 139 of the firstlight source 140 may not be connected to the circuit board 150.

FIG. 2C is a partial view of the composite light-emitting layer of thebacklight module of FIG. 2A. FIG. 2D is a diagram showing the positionalrelationship between a first light source, a first circuit, and abracket of a button structure of the backlight module of FIG. 2A.Referring to FIG. 2C, the first light source 140 corresponding to thesingle button structure is located at a position corresponding to thelight-transmitting region 138, and the first circuit 139 coupled to thefirst light source 140 is distributed along the light-shielding pattern133 on the light-shielding plate 134. Referring to FIG. 2D, in thepresent embodiment, the first light source 140 is located within therange corresponding to the opening 16 of the bracket 15 andcorresponding to the light-transmitting portion 11 a of the keycap 11.The majority of the first circuit 139 is located at a position outsidethe projection of the keycap 11, while a portion of the first circuit139 under the keycap 11 is arranged at a position corresponding to thebracket 15 where the openings 16 and 18 are not formed (i.e., thenon-opening region of the bracket 15). Thus, the layout of the firstcircuit 139 may be hidden under the bracket 15. Since the first circuit139 of the composite light-emitting layer 130 a is arrangedcorresponding to the main body of the bracket 15 to avoid the openings16 and 18, the first circuit 139, for the user, could be invisiblethrough the light-transmitting region 138 and barely impact the opticaleffects.

As shown in FIG. 2C and FIG. 2D, the first light source 140 may includea plurality of light-emitting diodes 143, 144, and 145. In anembodiment, the light-emitting diodes 143, 144, and 145 emit light ofdifferent wavelengths, such as red, green, and blue, but are not limitedthereto. The light-emitting diodes 143, 144, and 145 are respectivelyconnected to three separate circuit layouts (collectively referred to asthe first circuit 139), such that the light-emitting states of thelight-emitting diodes 143, 144, and 145 may be individually andindependently controlled, thus achieving combinations of single-colorlight emission or mixed light emission. That is, a plurality oflight-emitting diodes having different colors (collectively referred toas the first light source 140) are disposed under a single button, andthe keycap 11 could exhibit various backlighting effects.

FIG. 3 is a partial cross-sectional view of a backlight module accordingto another embodiment of the invention. Referring to FIG. 3 , the majordifference between a backlight module 100 b of FIG. 3 and the backlightmodule 100 a of FIG. 2B is that, in the present embodiment, the firstcircuit 139 is connected to the circuit board 150 via a connector 152.The film 135 and the first circuit 139 thereon may be easily insertedinto the connector 152 coupled to the circuit layout of the circuitboard 150 at the end 132 of the composite light-emitting layer 130 a tobe electrically connected to the circuit board 150. It should be notedthat the circuit board 150, as depicted in FIG. 3 , is a single-layercircuit board, and the connector 152 is disposed under the circuit board150 in a folding manner to connect the end 132 of the first circuit 139.In other embodiments, the circuit board 150 may be a double-layercircuit board, and the connector 152 may be directly mounted on thelower surface of the circuit board 150 without folding the circuit board150.

FIG. 4A is an exploded view of a backlight module according to anotherembodiment of the invention. FIG. 4B is a partial cross-sectional viewof the backlight module of FIG. 4A. Referring to FIG. 4A and FIG. 4B, inthe present embodiment, the first light source 140 and the light guideplate 120 of a backlight module 100 c are located on the same side ofthe light-transmitting substrate (i.e., the film 135). The light guideplate 120 has a hole 122, and the first light source 140 is disposed onthe surface of the light-shielding plate 134 facing the light-reflectingplate 110 and corresponding to the hole 122. The first light source 140could be arranged in the hole 122 or disposed on the periphery of thehole 122. The light emitted by the first light source 140 is adapted toenter the light guide plate 120, be reflected by the light-reflectingplate 110, and then be emitted through the light-transmitting region138. In addition, the first light source 140 on the light-shieldingplate 134 is disposed at a position corresponding to the light-shieldingpattern 133, such that the light of the first light source 140 could bereflected back into the light guide plate 120 by the light-reflectingcoating 136 and be uniformly distributed over the entire light guideplate 120, and leakage from the light-shielding coating 137 may beprevented as well.

In the present embodiment, light emission toward the light guide plate120 by the side-view light source may be achieved by the first circuit139 and the first light source 140 disposed on the light-shielding plate134, so as to obtain the light path similar to the second light source160 shown in FIG. 2A and FIG. 2B. Therefore, the flexible circuit board150 and the second light source 160 of FIG. 2A and FIG. 2B are notrequired for the backlight module 100 c of the present embodiment,thereby reducing the thickness thereof. That is to say, the first lightsource 140 of the present embodiment does not function as independentbacklighting for a single button, but replaces the side-view lightsource to make the light emitted by the first light source 140 enter thelight guide plate 120, such that a backlighting effect with uniform andeven brightness could be obtained via the first light source 140.

FIG. 4C is a partial cross-sectional view of a backlight moduleaccording to another embodiment of the invention. Referring to FIG. 4C,in the present embodiment, a composite light-emitting layer 130 c 1 of abacklight module 100 c 1 is disposed under the light guide plate 120 andmay be used as a light-reflecting plate of the backlight module 100 c 1.Since the bracket of the button structure is disposed above thebacklight module 100 c 1, the light guide plate 120 is disposed betweenthe bracket and the composite light-emitting layer 130 c 1. Thelight-shielding plate 134 may be further disposed above the light guideplate 120. The light emitted by the composite light-emitting layer 130 c1 under the light guide plate 120 is adapted to enter the interior ofthe light guide plate 120 and to be distributed over the light guideplate 120, until the light is emitted out from the top surface of thelight guide plate 120 not covered by the light-shielding coating 137 andemitted toward the button structure.

The composite light-emitting layer 130 c 1 includes a light-transmittingsubstrate 111, and a first circuit 112, a first light source 170, and afirst passivation layer 172 disposed on the light-transmitting substrate111. The first light source 170 is electrically connected to the firstcircuit 112. The first circuit 112, the first light source 170, and thelight guide plate 120 are located on the same side (such as the uppersurface) of the light-transmitting substrate 111. The light guide plate120 has a hole 123, and the first light source 170 on thelight-transmitting substrate 111 is disposed at a position correspondingto the hole 123. In an embodiment, the first light source 170 isarranged in the hole 123 or is located on the periphery of the hole 123.The first passivation layer 172 covers the first circuit 112 to preventthe damaged circuit pattern for the first light source 170. The firstpassivation layer 172 may be a light-reflecting coating (such as whitepaint) or a light-reflecting polymer film, which could reflect lightback into the light guide plate 120 and prevent the first circuit 112layout from affecting the optical effects of the backlight module 100 c1.

The first light source 170 is, for example, exposed outside the firstpassivation layer 172 to prevent the first passivation layer 172 fromshading the light emitted from the first light source 170 andinterfering the light coupling of the light guide plate 120. Inaddition, the lower surface of the light-transmitting substrate 111 isprovided with a light-shielding coating 117 as a light-shielding patternof the composite light-emitting layer 130 c 1. The light-shieldingcoating 117 and the first light source 170 are located on opposite sidesof the light-transmitting substrate 111. The light-shielding coating 117is, for example, fully coated on the lower surface of thelight-transmitting substrate 111 to prevent the light leakage from thebottom of the composite light-emitting layer 130 c 1. That is, thereflective first passivation layer 172 is arranged at the top of thecomposite light-emitting layer 130 c 1, and the light-shielding coating117 (i.e., a light-shielding pattern) is arranged at the bottom thereof.Thus, the composite light-emitting layer 130 c 1 may be used as alight-reflecting plate of the backlight module 100 c 1 while providing alight-emitting function.

The above embodiments are described with the composite light-emittinglayer separately providing the function of top-view light source orside-view light source; however, in other embodiments of the invention,both kinds of the light sources may be integrated into a singlecomposite light-emitting layer. FIG. 5 to FIG. 7 are partialcross-sectional views of various backlight modules according to otherembodiments of the invention. Similarly, the button structure is notshown in the following drawings, but it should be understood that thebacklight modules below are disposed under the button structure toprovide a backlit button. The same or similar components as the previousembodiments are represented by the same reference numerals in thefollowing embodiments.

Referring first to FIG. 5 , in a backlight module 100 d of the presentembodiment, a composite light-emitting layer 130 d includes the film135, and the first circuit 139, the first light source 140, and thefirst passivation layer 142 disposed on the film 135. The compositelight-emitting layer 130 d further includes a second light source 180, asecond circuit 182, and a second passivation layer 184. In the presentembodiment, the film 135 is a light-transmitting substrate, and thefirst circuit 139, the first light source 140, the second circuit 182,and the second light source 180 are disposed on the same side surface ofthe light-transmitting substrate (the film 135), and the light source140 and the second light source 180 are electrically connected to thefirst circuit 139 and the second circuit 182, respectively. Similar tothe first passivation layer 142 covering the first circuit 139, thesecond passivation layer 184 covers the second circuit 182, such that atleast a portion of the second circuit 185 is located between the secondpassivation layer 184 and the light-transmitting substrate (the film135) to avoid damage to the circuit layout. The first light source 140and the second light source 180 are located on the same side of thelight-transmitting substrate (the film 135). The first circuit 139 andthe second circuit 182 may be formed simultaneously on the film 135, andthe first passivation layer 142 and the second passivation layer 184could be disposed on the first circuit 139 and the second circuit 182 ina single step. Therefore, the first circuit 139 and the second circuit182 may be made of the same material, and the first passivation layer142 and the second passivation layer 184 may be the same film coveringthe different regions.

The first light source 140 and the second light source 180 are disposedon the surface of the film 135 that is distal to the light guide plate120 (i.e., the upper surface of the film 135). The light-reflectingcoating 136 and the light-shielding coating 137 that are collectivelyused as the light-shielding pattern are disposed above the first lightsource 140, for example. The light emitted by the first light source 140is emitted upward and then reflected by the light-reflecting coating 136so as to enter the light guide plate 120 and be reflected again by thereflective plate 110, until the light is emitted out from a portion ofthe light guide plate 120 not shaded by the light-shielding coating 137,thereby obtaining the uniform light emission over the backlight module100 d. Since the upper portion of the second light source 180 is notshaded, the emitted light could directly travel toward a directionopposite to the light guide plate 120, thereby upward illuminating asingle button. The first light source 140 is adapted to emit lighttoward the light guide plate 120 to provide an overall backlighting withuniformity for replacing the side-view light source; the second lightsource 180 is used as a top-view light source for providing independentand localized backlighting for special buttons (e.g., hot keys). Thesecond light source 180 may include a plurality of light-emitting diodes(not shown) that emit light having different wavelengths to achieve acombination of light emission with various colors. In addition, the film135 may further have a light-shielding pattern under the second lightsource 180 to further prevent the light of the second light source 180from entering the light guide plate 120 and affecting the colored lightmixing. In this way, the backlight module 100 d disposed under thebutton structure could deliver the even and uniform backlighting to theentire keyboard and provide a specific button with the directionalbacklighting via the composite light-emitting layer 130 d, therebyexhibiting various backlighting effects.

Referring to FIG. 6 , the major difference between a backlight module100 e of FIG. 6 and the backlight module 100 d of FIG. 5 is that, in thepresent embodiment, a light guide plate 120 e further has a plurality ofmicrostructures 124. In detail, the microstructures 124 are separatedfrom each other, and could be arranged on the surface of the light guideplate 120 e away from the first light source 140 and corresponding tothe first light source 140, such that the optical path could be forchanged to uniformly distribute the light and to directionally correctthe optical effect. In an embodiment, the microstructures 124 of thelight guide plate 120 e are concave-convex microstructures having acontour, for example, of a concave prism, an annular V groove, a dot, acolumn, a cone, a pyramid, or a combination of the above, therebyenabling the increased light refraction or scattering to take place onthe lower surface of the light guide plate 120 e to change thetransmission direction of the light and distribute the light uniformly.The microstructures 124 could be disposed on the lower surface of thelight guide plate 120 e only at a position corresponding to the firstlight source 140, or could be disposed on the entire lower surface ofthe light guide plate 120 e. In addition, the microstructures 124 of thelight guide plate 120 e may be disposed at a position corresponding tothe light-transmitting character portion of the keycap, such themicrostructures 124 are, for example, distributed under the opening ofthe bracket of the button structure to adjust the exit angle of thelight, thereby illuminating the rear side of the keycap through theopening of the bracket.

Referring to FIG. 7 , the major difference between a backlight module100 f of FIG. 7 and the backlight module 100 d of FIG. 5 is that, in thepresent embodiment, the first light source 141 and the second lightsource 181 of the backlight module 100 f are disposed on the surface ofthe light-shielding plate 134 facing toward the light-reflecting plate110. That is, the first light source 141, the second light source 181,and the light guide plate 120 are located on the same side of thelight-shielding plate 134. The first light source 141 and the secondlight source 181 are disposed on the lower surface of the film 135. Thelight guide plate 120 has the holes 122, and the first light source 141and the second light source 181 are disposed at the positionscorresponding to the holes 122. For example, the first light source 141and the second light source 181 are configured into the holes 122, orlocated on the periphery of the holes 122, so that the upper surface ofthe film 135 of the light-shielding plate 134 could be flat withoutprotrusions caused by the light sources. The light-reflecting coating136 and the light-shielding coating 137 are disposed above the firstlight source 141. Similarly, the light emitted by the first light source141 is emitted upward and then reflected by the light-reflecting coating136 to enter the light guide plate 120, and then is reflected by thereflective plate 110 again, until the light is extracted out of thelight guide plate 120, thereby providing the uniform illumination. Thesecond light source 181 that is not shaded emits the light directly andtoward a direction opposite to the light-reflecting plate 110, so as toachieve the directional and independent backlighting effect for aspecific button.

FIG. 8 is a partial cross-sectional view of the button structure with abacklight module according to another embodiment of the invention.Referring to FIG. 8 , in the embodiment, the button structure 10 of thelight-emitting keyboard 5 (marked in FIG. 1A) includes a bracket 15 withat least one opening 18, a keycap 11, a support assembly 12 and acircuit layer 14. The keycap 11 is connected to the bracket 15 via thesupport assembly 12. The circuit layer 14 is disposed between the keycap11 and the bracket 15. A backlight module 200 is disposed under thebracket 15.

In the embodiment, the backlight module 200 includes a compositelight-emitting layer 210 and a spacing layer 220. The compositelight-emitting layer 210 includes a substrate 212, at least one lightsource 211 and at least one circuit 215. The substrate 212 may be alight-transmitting substrate, which is, for example, a PET substrate,but material of the substrate 212 is not limited thereto. However, inother embodiments, the substrate 212 can be a light-shielding substrate,it is not limited thereto.

The at least one light source 211 is disposed on an upper surface 213 ofthe substrate 212 and located under the keycap 11. In addition, thelight source 211 functions as, for example, a top-view light source 211such that light emitted from the light source 211 is transmittedupwardly to the light-transmitting portion 11 a of the keycap 11. Insome embodiment, the light source 211 may be a chip-scale packaged LEDor mini LED.

Moreover, the at least one circuit 215 is disposed on the upper surface213 of the substrate 212 and electrically connected to the at least onelight source 211. In some embodiments, two light sources 211 which arerespectively coupled to the circuits 215 are arranged on the substrate212. Certainly, in other embodiments, the number of the light source 211can be one or more than two, which is not limited thereto.

As shown in FIG. 8 , in the embodiment, the backlight module 200 furtherincludes a passivation layer 216. The passivation layer 216 is disposedon the upper surface 213 of the substrate 212 and covers the circuit 215and the light source 211, such that at least a portion of the lightsource 211 and the circuit 215 are located between the passivation layer216 and the substrate 212 so as to protect both of the circuit 215 andthe light source 211, thereby preventing an open circuit or a shortcircuit caused by the damaged circuit on the substrate 212. Thepassivation layer 216 is, for example, a flexible polymer film having athickness less than the thickness of the substrate 212.

The spacing layer 220 is disposed between the composite light-emittinglayer 210 and the bracket 15, wherein the spacing layer 220 includes atleast one hole 224 corresponding to the at least one light source 211and the at least one opening 18 of the bracket 15. The number of thehole 224 is, for example but not limited thereto, equal to that of thelight source 211; that is, the spacing layer 220 may have two holes 224.The light sources 211 are located in the holes 224 of the spacing layer220.

As compared with the conventional backlight module which has theside-view light source coupled to the FPC and retained in the connectinghole of the stacked light guide plate and the reflective plate from therear side thereof, the light source 211 of the backlight module 200 isthe top-view light source such that the conventional light guide plateand the through hole of the reflective plate are not required, and thethickness of the backlight module 200 can be reduced and the opticaleffect can be enhanced as well.

In the embodiment, an orthographic projection of the elastic body 13projected onto the substrate 212 is not overlapped with an orthographicprojection of the light source 211 projected onto the substrate 212. Inother words, the light source 211 is not located directly under theelastic body 13, but could be arranged beneath the support assembly 12.In order to prevent the light source 211 being hit by the supportassembly 12 (scissor-like mechanism) when the keycap 11 is presseddownwardly, the spacing layer 220 is disposed between the substrate 212and the bracket 15. Due to the spacing layer 220, a distance between thesubstrate 212 and the bracket 15 becomes greater, such that the lightsource 211 does not protrude from a top surface of the bracket 15.Therefore, the possibility that the light source 211 is hit by thesupport assembly 12 when the keycap 11 is pressed downwardly can bereduced.

Specifically, the top surface of the spacing layer 220 is higher thanthe top surface of the light source 211. In an embodiment, a thicknessT1 of the spacing layer 220 is greater than or equal to a thickness T2of the light source 211, such that the light source 211 does notprotrude from a top surface 222 of the spacing layer 220 and does notextend into the opening 18 of the bracket 15. However, the thicknessesT1 and T2 of the spacing layer 220 and the light source 211 are notlimited thereto.

Moreover, in the embodiment, the backlight module 200 further includes afirst light-reflecting coating 240 and a first light-shielding coating245. The first light-reflecting coating 240 is disposed on the entirelower surface 214 of the substrate 212, and the first light-shieldingcoating 245 is disposed under the first light-reflecting coating 240, sothat the first light-reflecting coating 240 is sandwiched between thesubstrate 212 and the first light-shielding coating 245. A part of lightemitted from the light sources 211 and passing through the substrate 212could be reflected upwardly by the first light-reflecting coating 240,while the first light-shielding coating 245 could prevent the light fromleaking from the rear side of the backlight module 200. In anembodiment, the first light-reflecting coating 240 is a white paint, andthe first light-shielding coating 245 is a black paint. The colors ofthe first light-reflecting coating 240 and the first light-shieldingcoating 245 are not limited to the disclosure.

The backlight module 200 further includes a second light-shieldingcoating 230 disposed on the top surface 222 of the spacing layer 220facing to the bracket 15. The second light-shielding coating 230 is ablack paint, for example. The backlight module 200 further includes anadhesive layer 260, disposed between the second light-shielding coating230 and the bracket 15 such that the backlight module 200 can be fixedto the button structure by the adhesive layer 260.

In addition, as shown in FIG. 8 , the keycap 11 includes a bottom plate11 b and a plurality of side plates 11 c protruding from the bottomplate 11 b. FIG. 9 is a projecting view of the light source, the bracketand the first light-shielding coating projected onto the keycap of FIG.8 . It is noted that a central part 11 d (FIG. 9 ) of the keycap 11 ismarked by a dotted line. Referring to FIG. 9 , in an embodiment, a shapeof the second light-shielding coating 230 is a frame shape, a projectionof the light source 211 projected onto the keycap 11 is located withinthe central part 11 d (dotted line zone) of the keycap 11, and aprojection of the second light-shielding coating 230 projected onto thekeycap 11 is located out of the central part 11 d of the keycap 11 andoverlaps with the side plates 11 c of the keycap 11. Because the secondlight-shielding coating 230 is located corresponding to a position ofedges of the keycap 11, the light emitted from the light source 211 canbe shielded by the second light-shielding coating 230 so as to preventthe light leakage from the edge of the keycap 11.

FIG. 10 to FIG. 15 are respectively partial cross-sectional views of thebutton structure with various backlight modules according to otherembodiments of the invention.

Referring FIG. 10 , the main difference between the backlight module 200of FIG. 8 and the backlight module 200 a of FIG. 10 is that, in theembodiment, the backlight module 200 a further includes a secondlight-reflecting coating 235. The second light-reflecting coating 235 isdisposed on the top surface 222 of the spacing layer 220, a projectionof the second light-reflecting coating 235 projected onto the keycap 11is located within a central part 11 d (the dotted line zone shown inFIG. 9 ) of the keycap 11, so that the second light-reflecting coating235 could overlap with the bottom plate 11 b of the keycap 11 but notoverlap with the side plates 11 c of the keycap 11 in a direction alongthe keycap 11 being pressed. The second light-reflecting coating 235 canhelp for reflecting light emitted from the light source 211 so as toenhance the light emitting efficiency. In addition, the secondlight-shielding coating 230 is stacked on a portion of the secondlight-reflecting coating 235 which is close to a position correspondingto the side plates 11 c of the keycap 11 so as to prevent the lightleakage from the edge of the keycap 11.

Referring to FIG. 11 , the main difference between the backlight module200 of FIG. 8 and the backlight module 200 b of FIG. 11 is that, in theembodiment, a portion of the light source 211 is located within theopening 18 of the bracket 15. A thickness T3 of the spacing layer 220 bof the backlight module 200 b is, for example, less than the thicknessT1 of the light source 211, such that the light source 211 protrudes outof the top surface 222 of the spacing layer 220 b and extends into theopening 18 of the bracket 15, while the top surface of the light source211 is still lower than the top surface of the bracket 15. Accordingly,a portion of the light source 211 is accommodated in the opening 18, andthe thickness of the backlight module 200 b can be further reduced. Inan embodiment, the light source 211 arranged within the opening 18 maynot protrude over a half of the thickness of the bracket 15.

Referring to FIG. 12 , the main difference between the backlight module200 of FIG. 8 and the backlight module 200 c of FIG. 12 is that, in theembodiment, the spacing layer 220 c of the backlight module 200 c is alight-shielding plate, for example, an Mylar plate. The color of thespacing layer 220 c is black or dark-colored such that the secondlight-shielding coating 230 of the backlight module 200 (as elaboratedin FIG. 8 ) is no longer required, such that the overall thickness ofthe backlight module 200 c can be reduced. The second light-reflectingcoating 235 is disposed on the top surface 222 of the opaque spacinglayer 220 c so as to reflect light upwardly. A projection of the secondlight-reflecting coating 235 projected onto the keycap 11 is located ina central part 11 d of the keycap 11. That is, at least a portion of thespacing layer 220 c is not covered by the second light-reflectingcoating 235.

Referring to FIG. 13 , the main difference between the backlight module200 of FIG. 8 and the backlight module 200 d of FIG. 13 is that, in theembodiment, the spacing layer 220 d of the backlight module 200 d is alight guide plate. The second light-reflecting coating 235 is disposedon a portion of the top surface 222 of the spacing layer 220 d atpositions corresponding to the edges of the keycap 11 (for example, theside plates 11 c of the keycap 11), and the second light-shieldingcoating 230 is stacked on the second light-reflecting coating 235. Theother portion (a central portion) of the top surface 222 of the spacinglayer 220 d corresponding to a position of the central part 11 d (i.e.,the dotted line zone shown in FIG. 9 ) of the keycap 11 is exposedwithout being shielded by the second light-reflecting coating 235 or thesecond light-shielding coating 230, such that light emitted from thelight source 211 is capable of passing through the other portion (thecentral portion) of the top surface 222 of the spacing layer 220 d andemitted upwardly to the keycap 11. In some embodiments, a portion of thesecond light-reflecting coating 235 close to the light source 211 is notcovered by the second light-shielding coating 230; that is, the secondlight-reflecting coating 235 could partially protrude from an edge ofthe frame-shaped light-shielding coating 230, thereby enhancing theluminance corresponding to a specified spot.

It is noted that the backlight module 200 d further includes a pluralityof microstructures 226 arranged on the bottom surface of the spacinglayer 220 d, such that the optical path of the light emitted from thelight source 211 could be modified so as to uniformly distribute thelight and to directionally correct the optical effect. In an embodiment,the microstructures 226 are concave or convex microstructures having acontour, for example, of a concave prism, an annular V groove, a dot, acolumn, a cone, a pyramid, or a combination of the above, therebyenabling the increased light refraction or scattering to take place onthe bottom surface of the light guide plate to change the transmissiondirection of the light and distribute the light uniformly.

Referring to FIG. 14 , the main difference between the backlight module200 d of FIG. 13 and the backlight module 200 e of FIG. 14 is that, inthe embodiment, the microstructures 226 of the backlight module 200 eare arranged on the top surface 222 of the spacing layer 220 e. Themicrostructures 226 are, for example, arranged at the positioncorresponding to the central part 11 d of the keycap 11. Similarly, theoptical path of the light emitted from the light source 211 could bemodified, so as to uniformly distribute the light and to directionallycorrect the optical effect.

Referring to FIG. 15 , the main difference between the backlight module200 b of FIG. 11 and the backlight module 200 f of FIG. 15 is that, inthe embodiment, the spacing layer 220 f is an encapsulation layer madeof a transparent or translucent resin, such as epoxy resins or UV inks.The spacing layer 220 f could be fabricated by printing or pouring aliquid polymeric material and then curing the material into a solidencapsulation. As shown in FIG. 15 , the spacing layer 220 f is disposedon the upper surface 213 of the substrate 212 and covers the circuit 215on the upper surface 213 of the substrate 212 and a lower part oflateral sides of the light source 211, such that the light source 211can be fixed to the substrate 212 firmly by the spacing layer 220 f. Inthe embodiment, the passivation layer 216 is disposed on the spacinglayer 220 f and the light source 211, and the light source 211 extendsinto the opening 18 of the bracket 15. In other embodiments, as thespacing layer 220 f further covers the entire light source 211 as wellas the circuit 215 for protection, the spacing layer 220 f couldfunction as both of the encapsulation layer and the passivation layer,and therefore, the additional passivation layer 216 is not requiredanymore.

FIG. 16 to FIG. 17 are partial cross-sectional views of variousbacklight modules according to other embodiments of the invention.Referring to FIG. 16 first, in the embodiment, the backlight module 200g further includes a connection tail 250 that might be coupled to anedge of the composite light-emitting layer 210. The connection tail 250is partially disposed on the substrate 212 and electrically connected tothe circuit 215. The connection tail 250 may include a polymer film witha circuit layer thereon, wherein the circuit layer could be a printedconductive paste or a patterned metal layer, such as printed silverwiring or a patterned copper foil, but it is not limited thereto. In anembodiment, the circuit 215 of the composite light-emitting layer 210and the circuit layer of the connection tail 250 are made of materialswith different conductivities or of different conductors. The circuitlayer of the connection tail 250 may face the circuit 215 on thesubstrate 212, so that the connection tail 250 could be electricallycoupled to the circuit 215 through a conductive adhesive 252 (forexample, ACF or hotbar soldering) therebetween. The connection tail 250can extend outwardly to an outer system (not shown) or the power supply(not shown), such that the light source 211 can be electricallyconnected to the outer system or the power supply through the connectiontail 250. In an embodiment, the connection tail 250 can then be insertedinto a connector or connected to an external circuit board of anotherdevice.

Referring to FIG. 17 , in the embodiment, the connection tail 250 h ofthe backlight module 200 h is a flexible or foldable connection tail,which could be folded from the upper surface 213 of the substrate 212 tothe lower surface 214 of the substrate 212 so as to reduce the dimensionof width or length of the backlight module 200 h. In that case, thefolded connection tail 250 h may allow for more flexibility in thedesign of the backlight module 200 h.

FIG. 18 is a projecting view of the light source, the first circuit, thesecond circuit and the first light-shielding coating projected onto thekeycap of the button structure with a backlight module according toanother embodiment of the invention. FIG. 19 is a partialcross-sectional view along A-A section of the light source, the firstcircuit, the second circuit of FIG. 18 . It is noted that a central part11 d of the keycap 11 in FIG. 18 is marked by a dotted line.

Referring to FIGS. 18 and 19 , in the embodiment, the compositelight-emitting layer 210 i of the backlight module 200 i includes thelight source 211, a first circuit 217 and a second circuit 218. As shownin FIG. 19 , the circuit 215 electrically connected to the light source211 includes the first circuit 217 and the second circuit 218. The lightsource 211, the first circuit 217 and the second circuit 218 are coveredand protected by the passivation layer 216. With reference to FIGS. 18and 19 , the first circuit 217 is electrically connected to the lightsource 211 and corresponds to the position of the central part 11 d ofthe keycap 11. The second circuit 218 is electrically connected to thefirst circuit 217 and extended outwardly and along the orthographicprojection of the two opposite side plates 11 c of the keycap 11. Theextended second circuit 218 may be further coupled to another lightsource and the corresponding circuit that are arranged under anotherkeycap adjacent to the keycap 11. In some embodiments, a material of thefirst circuit 217 is different from a material of the second circuit218, and a width of the first circuit 217 is less than a width of thesecond circuit 218. The first circuit 217 and the second circuit 218 maybe made of materials with different conductivities. The first circuit217 is, for example, made of a conductive component that could providethe improved adhesion to the light source 211, as compared with thesecond circuit 218.

FIG. 20 is a partial cross-sectional view of a light-emitting keyboardaccording to an embodiment of the invention. Referring to FIG. 20 , alight-emitting keyboard 5′ includes at least one button structure 10 anda backlight module 300 located under the button structure 10. Lightprovided by the backlight module 300 illuminates the rear side of thebutton structure 10 to provide the user with an identification orvarious visual effects. It is noted that FIG. 20 only shows a part ofthe light-emitting keyboard 5′ (one button structure 10 and acorresponding part of the backlight module 300). However, thelight-emitting keyboard 5′ is exemplified by, for example but notlimited to, a keyboard of a notebook computer.

The button structure 10 includes a keycap 11, a support assembly 12, anelastic body 13, a circuit layer 14, and a bracket 15. The keycap 11 isdisposed on the bracket 15 and connected to the bracket 15 via thesupport assembly 12. The support assembly 12 is disposed between thekeycap 11 and the bracket 15. The respective ends of the supportassembly 12 are connected to the keycap 11 and the bracket 15, such thatthe keycap 11 is stably moved up and down relative to the bracket 15 viathe connection of the support assembly 12. The support assembly 12 is,for example but not limited to, a scissor-like mechanism that includestwo supporting pieces pivotally assembled together.

The circuit layer 14 is disposed between the at least one keycap 11 andthe bracket 15. The circuit layer 14 is, for example, a flexiblemembrane circuit in a multi-layered structure having a conductiveportion as a switching region to be triggered by the elastic body 13.The elastic body 13 is disposed between the keycap 11 and the circuitlayer 14, and provides a restoring force to drive the keycap 11 move upand return to its released state.

The backlight module 300 is disposed under the button structure 10, andincludes a composite light-emitting layer 310, a light guide plate 370and a light-shielding layer 380.

FIG. 21 is a partial cross-sectional view of a backlight module of FIG.20 . Referring to FIG. 21 , in the embodiment, the compositelight-emitting layer 310 includes a substrate 320, a conductive layer330, a reflective layer 340 and at least one light source 350. In theembodiment, the substrate 320 is a light-shielding substrate 322, forexample, a black Mylar film, but the type of the substrate 320 is notlimited thereto.

The conductive layer 330 is disposed on the substrate 320, and theconductive layer 330 includes circuits 337 and patterned structures 338.The light source 350 is electrically connected to the circuits 337, andthe patterned structures 338 are electrically insulated from the lightsource 350.

FIG. 22 is a top view of the conductive layer and the bracket of thelight-emitting keyboard of FIG. 20 . Referring to FIG. 22 , in theembodiment, shapes of the patterned structures 338 are grid shapes, butthe shapes of the patterned structures 338 are not limited thereto. Inthe embodiment, the patterned structures 338 are distributed throughoutthe substrate 320 so as to improve structural strength of the backlightmodule 300 (FIG. 21 ). Hence, the backlight module 300 is not easy to bebent or physically deformed. In addition, in an embodiment, thepatterned structures 338 could be connected to the bracket 15 throughconductive members (not shown) so that the patterned structures 338 aregrounded.

As shown in FIG. 22 , the substrate 320 has a first long side 30 (forexample, an upper long side), a second long side 32 (for example, alower long side), a first short side 34 (for example, a left shortside), and a second short side 36 (for example, a right short side). Thefirst long side 30 and the second long side 32 are opposite to eachother, and the first short side 34 and the second short side 36 areopposite to each other.

In the embodiment, the composite light-emitting layer 310 couldpartitioned into several rows with respective lighting circuitry, suchas rows R1-R6. The at least one light source 350 includes first lightsources 351, second light sources 352, third light sources 353, fourthlight sources 354, fifth light sources 355 and sixth light sources 356arranged in rows R1-R6, respectively. The first light sources 351 areclose to the first long side 30, and the sixth light sources 356 areclose to the second long side 32.

The circuits 337 includes circuitry 331 corresponding to the row R1connecting the first light sources 351 in parallel, circuitry 332corresponding to the row R2 connecting the second light sources 352 inparallel, circuitry 333 corresponding to the row R3 connecting the thirdlight sources 353 in parallel, circuitry 334 corresponding to the row R4connecting the fourth light sources 354 in parallel, circuitry 335corresponding to the row R5 connecting the fifth light sources 355 inparallel, and circuitry 336 corresponding to the row R6 connecting thesixth light sources 356 in parallel.

FIG. 23 is a partial enlarged view of FIG. 22 . Specifically, FIG. 23 isa partial enlarged view corresponding to one of the third light sources353 of FIG. 22 . Referring to FIG. 23 , the circuitry 333 includes twowires 339, one of the two wires 339 is connected to a positive electrodeof the light source 353, the other of the two wires 339 is connected toa negative electrode of the light source 353. The patterned structures338 are electrically insulated from the circuitry 333.

Referring back to FIG. 21 , in the embodiment, the reflective layer 340is a light-reflecting film 344. In the embodiment, the light reflectingfilm 344 may be a light-reflecting film, for example, a film doped withlight-reflecting or diffusing particles. In another embodiment, thereflective layer 340 may be a light-reflecting coating or a film withlight-reflecting coating, the type of the reflective layer 340 is notlimited thereto.

The reflective layer 340 is conformally disposed on the conductive layer330, and a part of the reflective layer 340 conformally disposed on thepatterned structures 338 functions as micro structures 346 protrudingfrom the flat surface, so as to reflect light uniformly and/or providebetter reflection effect. Therefore, in the embodiment, the patternedstructures 338 of the conductive layer 330 not only improve thestructural strength of the backlight module 300, but also facilitate theformation of micro structures 346, such that the backlight module 300may provide uniform lighting effect.

In addition, the light guide plate 370 is disposed on the reflectivelayer 340, and includes at least one hole 372 where the at least onelight source 350 is located in. The light-shielding layer 380 disposedon the light guide plate 370 has a surface provided with alight-reflecting layer 382 and a light-shielding layer 384, and thelight-reflecting layer 382 is disposed between the light source 350 andthe light-shielding layer 384. The light-reflecting layer 382 could be awhite paint or white ink layer, while the light-shielding layer 384could be a black paint or black ink layer. In another embodiment, thelight-reflecting layer 382 may extends outside an edge of thelight-shielding layer 384, so that the light-reflecting layer 382 couldhave a single pattern area larger than that of the light-shielding layer384.

In the embodiment, light emitted from the light source 350 may betransmitted upwardly, reflected to the light guide plate 370 by thelight-reflecting coating 382, transmitted in the light guide plate 370,reflected by the micro structures 346 of the reflective layer 340, andemitted to the keycap 11 (FIG. 20 ).

In addition, in FIG. 22 , the composite light-emitting layer 310 (FIG.20 ) further includes a first resistor 361, a second resistor 362, athird resistor 363, a fourth resistor 364, a fifth resistor 365 and asixth resistor 366 located in the row R6.

FIG. 24 is a circuitry diagram of the resistors, light sources, andcircuits of FIG. 22 . Referring to FIGS. 22 and 24 , the first resistor361 is electrically connected to a group of the first light sources 351in series via the circuitry 331, the second resistor 362 is electricallyconnected to a group of the second light sources 352 in series via thecircuitry 332, the third resistor 363 is electrically connected to agroup of the third light sources 353 in series via the circuitry 333,the fourth resistor 364 is electrically connected to a group of thefourth light sources 354 in series via the circuitry 334, the fifthresistor 365 is electrically connected to a group of the fifth lightsources 355 in series via the circuitry 335, and the sixth resistor 366is electrically connected to a group of the sixth light sources 356 inseries via the circuitry 336.

In the embodiment, the circuitry 331, 332, 333, 334, 335 and 336 are inparallel connection, and each is electrically connected to a connector368 which may connect to a processor (not shown) of a notebook computer(not shown).

It is noted that in the keyboard, a key (not shown) corresponding to therow R1 may be a function key (for example, one of F1-F12 keys). Becausethe function key has a smaller size, an area of the opening 16 of thebracket 15 (as shown in FIG. 20 ) below the function keycap is smallerthan that of a normal key. In order to provide sufficient backlightingbrightness for the function key, the current of the circuitry 331 needsto be greater. That is, a resistance of the first resistor 361 should besmaller.

In addition, a key (not shown) corresponding to the row R6 may be aspace bar which has a greater size, such that an area of the opening ofthe bracket 15 below the space bar is greater than that of the normalkey. In order to provide uniform brightness for the keys correspondingto the row R6, the current of the circuitry 336 needs to be smaller.That is, a resistance of the sixth resistor 366 should be greater.

In the embodiment, a resistance of the first resistor 361 is smallerthan or equal to a resistance of the second resistor 362, the resistanceof the second resistor 362 is smaller than a resistance of the thirdresistor 363, the resistance of the third resistor 363 is smaller thanor equal to a resistance of the fourth resistor 364, the resistance ofthe fourth resistor 364 is smaller than a resistance of the fifthresistor 365, and the resistance of the fifth resistor 365 is smallerthan or equal to a resistance of the sixth resistor 366. Therefore, thelight-emitting keyboard 5′ can provide uniform optical effect.

In one embodiment, each one of the resistances of the first resistor andthe second resistor is 115 ohm, each one of the resistances of the thirdresistor and the fourth resistor is 124 ohm, and each one of theresistances of the fifth resistor and the sixth resistor is 140 ohm.Certainly, the resistances of the resistors are not limited thereto.

FIG. 25 is a partial cross-sectional view of a backlight module of alight-emitting keyboard according to an embodiment of the invention.Referring to FIG. 25 , in the embodiment, main differences between thebacklight module 300 of FIG. 21 and a backlight module 300 a of FIG. 25are that, in the embodiment, the substrate 320 a includes alight-transmitting film 324 and a light-shielding coating 326 disposedbelow the light-transmitting film 324 to avoid light leakage. Inaddition, the light source 350 is covered by an encapsulation 358 thatcould protect the chip or function as a lens. Moreover, the reflectivelayer 340 a is a light-reflecting coating 342, for example, a white inkor white paint layer.

Similarly, the backlight module 300 a includes the patterned structures338 of the conductive layer 330 so that the structural strength of thebacklight module 300 a can be improved. Moreover, the reflective layer340 a is conformally disposed on the conductive layer 330 so as to formmicro structures 346, such that the backlight module 300 a may provideuniform lighting effect.

FIG. 26 is a top view of the light sources, the light guide plate andthe bracket of the light-emitting keyboard of FIG. 20 . FIG. 27 is apartial enlarged view of zone E of FIG. 26 .

Referring to FIG. 26 and FIG. 27 , light-emitting keyboard 5′ can beseparated to a first zone E1, a second zone E2 and a third zone E3. Asthe light guide plate 370 cannot be seen in FIG. 26 , the relativeposition of the light guide plate 370 and the composite light-emittinglayer 310 is shown in FIG. 21 . The first zone E1, the second zone E2and the third zone E3 are arranged along the first long side 30, and thesecond zone E2 is located between the first zone E1 and the third zoneE3. In the embodiment, the first zone E1 is close to the first shortside 34, and the third zone E3 is close to the second short side 36. Arange of the first zone E1 is smaller than a range of the second zoneE2, and a range of the third zone E3 is smaller than the range of thesecond zone E2.

It is noted that, when the light guide plate 370 is assembled to thecomposite light-emitting layer 310, positioning posts (not shown) of thelight guide plate 370 are located at four corners of the light guideplate 370, positions of rows R1 and R6 corresponding to the first zoneE1 and the third zone E3 which are close to the four corners areparticularly prone to exist assembly deviation with the compositelight-emitting layer 310. In order to solve assembly deviation betweenthe light guide plate 370 and the composite light-emitting layer 310,the light guide plate 370 is provided with holes 372 (FIG. 27 ) withdifferent sizes for two adjacent light sources 356 a, 356 b (FIG. 27 )of the composite light-emitting layer 310.

It is noted that, the zone E in FIG. 27 indicates a combination of thefirst zone E1 and the second zone E2 in the row R6. Specifically, asshown in FIG. 27 , the light source 356 a corresponding to the firstzone E1 and the light source 356 b corresponding to the second zone E2.The light source 356 a is close to the first short side 34 (FIG. 26 )and located between the light source 356 b and the first short side 34.The light guide plate 370 includes a first hole 374 located in the firstzone E1 and a second hole 376 located in the second zone E2. The lightsource 356 a located in the first hole 374, and the light source 356 blocated in the second hole 376.

In the embodiment, a size of the first hole 374 is greater than a sizeof the second hole 376. For instance, a length L1 of the first hole 374along the first long side 30 is greater than a length L2 of the secondhole 376 along the first long side 30. In addition, a length L3 of thefirst hole 374 along the first short side 34 could be greater than alength L4 of the second hole 376 along the first short side 34.

In the embodiment, the first hole 374 has a greater size so as toprovide more room for the light source 356 a. Hence, the light source356 a can be successfully inserted into the first hole 374 of the lightguide plate 370 without interference by assembly tolerance when thelight guide plate 370 is assembled to the composite light-emitting layer310.

It is noted that, although it only shows dimensional relation of thefirst hole 374 in the first zone E1 and the second hole 376 in thesecond zone E2, dimensional relation of the hole in the third zone E3and the second hole 376 in the second zone E2 are the same.

Therefore, as shown in FIG. 26 , in an embodiment, the holes (as thefirst hole 374 in FIG. 27 ) in the rows R1 and R6 corresponding to thefirst zone E1 and the third zone E3 may have greater size than the holescorresponding to the second zone E2 (as the second hole 376 in FIG. 27 )and the holes in rows R2-R5 corresponding to the first zone E1 and thethird zone E3. Therefore, the light guide plate 370 can successfully andeffectively assembled to the composite light-emitting layer 310, suchthat assembly yield of the light guide plate 370 and the compositelight-emitting layer 310 in mass production can be improved.

Based on the above, the backlight module and the light-emitting keyboardof the invention includes the patterned structures of the conductivelayer, the patterned structures not only improve the structural strengthof the backlight module, but also help to form micro structures of thereflective layer such that the backlight module may provide uniformlighting effect.

Lastly, it should be mentioned that: each of the above embodiments isonly used to describe the technical solutions of the invention and isnot intended to limit the invention; and although the invention isdescribed in detail via each of the above embodiments, those havingordinary skill in the art should understand that: modifications maystill be made to the technical solutions recited in each of the aboveembodiments, or portions or all of the technical features thereof may bereplaced to achieve the same or similar results; the modifications orreplacements do not make the nature of corresponding technical solutionsdepart from the scope of the technical solutions of each of theembodiments of the invention.

What is claimed is:
 1. A light-emitting keyboard, comprising: a bracket;at least one keycap disposed on the bracket and connected to the bracketvia a support assembly; a circuit layer disposed between the keycap andthe bracket; a composite light-emitting layer disposed under thebracket, comprising: a substrate; a conductive layer disposed on thesubstrate and comprising a circuit and patterned structures; areflective layer conformally disposed on the conductive layer; and atleast one light source located under the at least one keycap andelectrically connected to the circuit.
 2. The light-emitting keyboard ofclaim 1, wherein the substrate is a light-shielding substrate.
 3. Thelight-emitting keyboard of claim 1, wherein the substrate comprises alight-transmitting film and a light-shielding coating disposed below thelight-transmitting film, and a portion of the circuit neighboring to thelight source is exposed by the reflective layer.
 4. The light-emittingkeyboard of claim 1, wherein the reflective layer is a light-reflectingcoating, a light-reflecting film or a film with light-reflectingcoating.
 5. The light-emitting keyboard of claim 1, wherein thepatterned structures are electrically insulated from the light sourceand are grounded.
 6. The light-emitting keyboard of claim 1, whereinshapes of the patterned structures are grid shapes, and a part of thereflective layer on the patterned structures forms micro structures. 7.The light-emitting keyboard of claim 1, wherein the compositelight-emitting layer has a first long side and a second long sideopposite to each other, the at least one light source comprises a firstlight source close to the first long side and a second light sourceclose to the second long side, the composite light-emitting layerfurther comprises a first resistor electrically connected to the firstlight source and a second resistor electrically connected to the secondlight source, and a resistance of the first resistor is smaller than aresistance of the second resistor.
 8. The light-emitting keyboard ofclaim 1, wherein the composite light-emitting layer has a first shortside, the at least one light source comprises a first light source and asecond light source, the first light source is close to the first shortside and located between the second light source and the first shortside, the light-emitting keyboard further comprises a light guide platelocated on the reflective layer, the light guide plate comprises a firsthole and a second hole, the first light source located in the firsthole, the second light source located in the second hole, and a size ofthe first hole is greater than a size of the second hole.
 9. Thelight-emitting keyboard of claim 8, wherein a length of the first holealong a long side of the composite light-emitting layer is greater thana length of the second hole along the long side.
 10. The light-emittingkeyboard of claim 8, wherein a length of the first hole along the firstshort side is greater than a length of the second hole along the firstshort side.
 11. A backlight module adapted to be disposed under a buttonstructure, wherein the backlight module comprises: a compositelight-emitting layer, comprising: a substrate; a conductive layerdisposed on the substrate and comprising a circuit and patternedstructures; a reflective layer conformally disposed on the conductivelayer; and at least one light source electrically connected to thecircuit; a light guide plate disposed on the reflective layer, andcomprising at least one hole, wherein the at least one light sourcelocated in the at least one hole; and a light-shielding layer disposedon the light guide plate.
 12. The backlight module of claim 11, whereinthe substrate is a light-shielding substrate.
 13. The backlight moduleof claim 11, wherein the substrate comprises a light-transmitting filmand a light-shielding coating disposed below the light-transmittingfilm.
 14. The backlight module of claim 11, wherein the reflective layeris a light-reflecting coating, a light-reflecting film or a film withlight-reflecting coating, and a portion of the circuit neighboring tothe light source is exposed by the reflective layer.
 15. The backlightmodule of claim 11, wherein the patterned structures are electricallyinsulated from the light source and are grounded.
 16. The backlightmodule of claim 11, wherein shapes of the patterned structures are gridshapes, and a part of the reflective layer on the patterned structuresforms micro structures.
 17. The backlight module of claim 11, whereinthe composite light-emitting layer has a first long side and a secondlong side opposite to each other, the at least one light sourcecomprises a first light source close to the first long side and a secondlight source close to the second long side, the composite light-emittinglayer further comprises a first resistor electrically connected to thefirst light source and a second resistor electrically connected to thesecond light source, and a resistance of the first resistor is smallerthan a resistance of the second resistor.
 18. The backlight module ofclaim 11, wherein the composite light-emitting layer has a first shortside, the at least one light source comprises a first light source and asecond light source, the first light source is close to the first shortside and located between the second light source and the first shortside, the at least one hole comprises a first hole and a second hole,the first light source located in the first hole, the second lightsource located in the second hole, and a size of the first hole isgreater than a size of the second hole.
 19. The backlight module ofclaim 18, wherein a length of the first hole along a long side of thecomposite light-emitting layer is greater than a length of the secondhole along the long side.
 20. The backlight module of claim 18, whereina length of the first hole along the first short side is greater than alength of the second hole along the first short side.